This application claims benefit of Japanese Application No. 2000-210193 filed in Japan on Jul. 11, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to an endoscope having parts-bonded sections each of which has members thereof bonded together using an adhesive.
2. Description of the Related Art
Endoscopes for medical use have been widely adopted in the past. The endoscope for medical use has an elongated insertion member thereof inserted into a body cavity in order to observe an intracavitary organ or has, if required, a therapeutic instrument passed through a therapeutic instrument channel thereof in order to perform any of various cures.
In particular, the endoscope for use in the medical field has an insertion member thereof inserted into a body cavity for the purpose of observation of an organ or has a therapeutic instrument passed through a therapeutic instrument channel thereof for the purpose of cures or treatments.
When a used endoscope or therapeutic instrument is reused for another patient, the endoscope equipment must be cleaned and sterilized after completion of examination or treatment in order to prevent inter-patient infection through the endoscope or therapeutic instrument.
In recent years, autoclaving (high-pressure steam sterilization) has become a mainstream of disinfection or sterilization of medical equipment. This is because autoclaving is no labor-intensive but is usable immediately after completion of sterilization and requires only a small running cost.
For example, Japanese Unexamined Patent Publication No. 8-56897 discloses a durable endoscope including a flexible sheathing tube that has portions thereof fastened using strings. The flexible sheathing tube will not be damaged despite contraction of the strings that derives from boiling sterilization or steam sterilization. The strings are short-fiber strings that are made of a synthetic resin and that exhibit a contraction ratio which is equal to or smaller than 14%. The contraction ratio is a ratio of the length of a string measured at the room temperature after the string is placed in steam of about 132xc2x0 C. to the length thereof measured at the room temperature before the string is placed therein.
When the flexible sheathing tube is used to shield, for example, a bending section, an adhesive is applied to the short-fiber strings in order to secure the flexible sheathing tube. As the adhesive, an adhesive resistive to high temperature is used to enable high-pressure steam sterilization of the endoscope.
However, if the flexible sheathing tube should be broken, the flexible sheathing tube will be replaced with a new one. Otherwise, parts-bonded sections may be heated in order to destroy an applied adhesive so that the members included in the parts-bonded sections will be disassembled in order to replace a built-in component of an endoscope with a new one or repair it. In this case, the heating may deteriorate the flexible sheathing tube. Consequently, it may become very hard to dismount the flexible sheathing tube, or members located near the parts-bonded sections of the flexible sheathing tube may be broken with heat.
By the way, the parts-bonded sections may not be heated, but mechanical force may be applied to the parts-bonded sections in order to destroy the adhesive so that the members included in the parts-bonded sections can be disassembled. In this case, the members located near the parts-bonded sections may be broken with the mechanical force.
Accordingly, an object of the present invention is to provide an endoscope offering excellent workability. The endoscope can be sterilized with high-pressure steam and easily modified or repaired even after components are bonded using adhesives.
Briefly, according to the present invention, there is provided an endoscope consisting mainly of a plurality of members, which constitute the endoscope, and parts-bonded sections each of which has at least members thereof bonded together using an adhesive. The temperatures of thermal destruction at which the adhesives included in the parts-bonded sections are thermally destroyed are made equal to or higher than the maximum temperature attained during a high-pressure steam sterilization process. Besides, the temperatures of thermal destruction are made equal to or lower than the heat-resistance temperatures above which members bonded together using the adhesives or members located near the bonded members included in the parts-bonded sections fail to resist heat. When an endoscope is sterilized with high-pressure steam, the parts-bonded sections will not be degraded with high-pressure steam. Moreover, when a component of the endoscope must be repaired or modified, the adhesive included in the parts-bonded section must be destroyed with heat. At this time, the bonded members and the members located near the parts-bonded section will not be broken.
The above and other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.